$\left(-4x - 8\right)^2 = \ ?$
Answer: $= \left(-4x - 8\right)\left(-4x - 8\right)$ $= -4x \cdot \left(-4x - 8\right) - 8 \cdot \left(-4x - 8\right)$ $= \left( -4x \cdot -4x \right) + \left( -4x \cdot -8 \right) + \left( -8 \cdot -4x \right) + \left( -8 \cdot -8 \right)$ $= 16x^2 + \left( -4x \cdot -8 \right) + \left( -8 \cdot -4x \right) + \left( -8 \cdot -8 \right)$ $= 16x^2 + \left( 32x + 32x \right) + \left( -8 \cdot -8 \right)$ $= 16x^2 + 64x + \left( -8 \cdot -8 \right)$ $= 16x^2 + 64x + 64$